Flexural bearing capacity of the full-scale bonded prestressed concrete beams and slabs under high temperature is analyzed by nonlinear method.The result shows that composite reinforcement index and effective prestress have little effect on M

A

u

/M

u

of bonded prestressed concrete beams and slabs

and concrete cover of prestressed reinforcement has significant effect on M

A

u

/M

u

.When the ratios of height to width are similar

and the concrete covers of reinforcement in the first row are the same

the biggest descent rate of flexural bearing capacity is almost 30%for 700 mm high beam after 3 h fi

re duration

comparing with 10%for 4500 mm high beam.Mechanical performance of large scale beams is better than small scale beams after high temperature.The calculation formula on M

A

u

/M

u

of bonded prestressed concrete slabs is established introducing the effect of concrete cover of prestressed reinforcement and prestress degree. The calculation formula on M

A

u

/M

u

of bonded prestressed concrete beams is also established considering the distances between the bottom of beams and the force points of prestressed reinforcement and nonprestressed reinforcement.